Introduflion. ix 



ably uot over oue-teiith is suited for the support of mollusks. The 

 island is. however, notable as the home of A. magna, Adams, the 

 largest shell of the whole Achatinella family. Specimens in our 

 cabinet measure iVz in. long. The whole number of species of 

 Achatinella on Lanai is 13, and they exhibit peculiarities of type. 



"Kauai. — This is the oldest and most verdant island of the 

 group. It lies to the west of Oahu and is separated from it by a 

 channel wider than occurs between an)- of the other islands. Its 

 extensive forests, luxuriant vegetation and moist climate render it 

 peculiarly well adapted for the abode of Achatinella ; and one 

 would naturally expect to find here a larger and, if possible, higher 

 development of the family. But we are doomed to disappointment. 

 The island yields no arboreal species. The shells are all terres- 

 trial, and those clas.sed with the Achatinella belong to the plainest 

 forms of the Amastra and Leptachatina groups ; 5 species to the 

 lormer and 18 to the latter group. Kauai, however, does furni.sh 

 a very peculiar and interesting group of large terrestrial shells, 

 remarkable for their elongate, turreted form. The generic name 

 Carelia has been provided for the group. It embraces 7 species. 

 Specimens of Carelia turricula, Migh., in riiy cabinet measure 3 in. 

 long. This group has no claims to a place in the Achatinellinae 

 family as classed by Mr. Gulick. It lacks the peculiar twist of the 

 columella and other generic characflers of that family. Living 

 specimens of the Carelia are now exceedingly rare, but at some 

 period in the history of Kauai they were very abundant. The 

 alluvial deposits near the coa.sts of portions of the island contain 

 multitudes of these shells in a semi-fossil state, which have been 

 washed from the mountains by the freshets of ages past. The 

 small neighboring island of Niihau also has a single species of 

 Carelia found in sand and mud deposits. No living specimens are 

 found there now. 



"Haw.'MI. — This island embraces within its bounds two-thirds 

 of the total area of the whole group. It is also supposed to be the 

 most recently formed of the islands. The volcanic forces are .still 

 at work here. Its extensive forests are as well adapted for the 

 support of Achatinella as those of any of the other islands. But 

 it furnishes only a single arboreal species and 5 terrestrial. The 

 arboreal species is A. physa. It was first described by Dr. New- 

 comb in Proceedings Zoological Society, London, 1853. In a 

 subse(|uent number of the same journal Mr. W. H. Pease refers to 



